On the other hand, the official gazette of Japanese Unexamined Patent Publication No. 2002-164686 discloses an open type magnetic shield method. A magnetic shield room is defined by walls on which a plurality of magnetic shield members, each of which comprises a plurality of strips of magnetic shield material on each other, are arranged perpendicularly along the walls parallel to each other so that the magnetic flux density (the magnetic field intensity) can be attenuated between the opposed faces of the magnetic shield members adjacent to each other.
However, it takes much labor and time to arrange a large number of magnetic shield strip members along the walls in parallel to each other while leaving a gap between them. Further, when an external force is applied to the magnetic shield members, the magnetic shield members are deformed.